Frozen Embryo Transfer (FET) in Natural Cycles or in Natural Cycles Controlled by Human Chorionic Gonadotropin (hCG) Administration

Cryopreserved-Thawed Embryo Transfer in Natural Cycle or in Natural Cycles Controlled by External Administration of hCG: a Prospective Randomized Study

The rational of the study is to assess the implantation, pregnancy and live birth rates after the transfer of frozen- thawed embryos in natural cycles with spontaneous Luteinizing Hormone (LH)/Progesterone rise or in natural cycles controlled by human chorionic gonadotropin (hCG) for final oocyte maturation and ovulation.

Inclusion Criteria:

• age <40
• BMI:18-29Kg/m2
• day 3 embryo transfers
• previously IVF or ICSI

Exclusion Criteria:

• irregular cycles
• oocyte donation cycles